There are both bar codes and token codes designed to represent a numerical character and/or a symbol for use in identification code sheets.
As is well known, a bar code is set up by a plurality of fine and thick bars regularly spaced and combined to represent a numerical character etc. According to the prior art, a bar code sheet set up by a combination of a plurality of fine and thick bars regularly spaced is characteristically accompanied by such drawbacks as a need for high level printing techniques on the sheet and which is very costly and requires an unnecessarily high level of accuracy for preparation.
Token code sheets for binary representation in terms of the locations of punched hole are accompanied by such drawbacks as a need of punching process and a low speed of reading relative to an optical and a magnetic types.
Other drawbacks inherent in the said types of sheet discussed are a limited capability of representing only a numerical character and a part for a character string, and a need of re-making the code content whenever an urgent change is needed to be made by the operators by code printer or a punch installed away from the site of operation, meaning substantial difficulties are encountered during data maintenance, especially for a large scale POS (Point Of Sales system).
There is also another known art represented by reading means to handle an identification code represented by a bar code system, according to U.S. patent application Ser. No. 316,936 (Japanese Patent Publication No. 21980 of 1978).
According to the prior art, bar codes are to be identified as to binary codes on the principle of finding both a finess/thickness and a location of the code bars, thus often resulting in a high likelihood of inducing reading errors; these types of codes are mostly used to represent, in general, numerical characters and rarely can handle even the letters of an alphabet. For this reason, the realization of these conventional means has not so far been achieved to cover a Kanzi-code under JIS (Japanese Industrial Standard) rule. According to the conventional art, there is also an absolute need for an exact reading of a finess/thickness and a location of the bars setting up bar codes, which means a likelihood of read errors according, depending on misprints of the code bars, elongation/shrinkage of the bar code paper, irregularity of the surfaces on which the bar code papers are to be pasted and a change in the reading angle of a senser relative to the bar code paper.
More recently, a new method of code-making is being developed, by which O to F is represented by coding properly the " " character. It should, however, be noted that the " " character involves, in coding thereof, such unsolved problems as a need for a specific direction of reading and specification of the same, because of the symmetrical composition of said character in both horizontal and vertical directions.